The invention relates to a device for connecting the plug-in base of a side-mounting luminaire to a carrier tube, in particular to the tube of a luminaire mast, it being possible for the plug-in base of the side-mounting luminaire to be connected to the carrier tube and to be fixed to the carrier tube by means of a securing element that can be inserted into the side-mounting luminaire from the outside inward, and it being possible for the securing element to be pressed against an abutment which effects clamping.
Such a device is disclosed in JP 10-012013A. A luminaire mast is present in whose upper open end a connecting bush is fixed. The outside diameter of the connecting bush is chosen such that this connecting bush is fixedly held in the open end of the luminaire mast and projects partly therefrom. The portion of the connecting bush projecting over the open end of the luminaire mast. A mast top unit luminaire is mounted on the portion of the connecting bush of smaller diameter projecting from the luminaire mast. For this purpose, this mast top unit luminaire has a plug-in base which fits the connecting bush. The outside diameter of the plug-in base corresponds to the outside diameter of the luminaire mast, the result being a smooth transition.
Provided on the plug-in base is a setscrew which acts as a securing element and can be screwed in from the outside inward so as to clamp the side-mounting luminaire on the luminaire mast. The setscrew can be screwed in up to an abutment which is formed by the outer wall of the connecting bush. It is known from experience that such clamps are not very stable if the material of the tube is selected to be as thin as possible for reasons of economy. A further disadvantage is that there is a need for a particular connecting bush which must be inserted both into the open end of the luminaire mast and into the plug-in base in order to bring about the connection. This means a greater outlay on labor.
In a construction known from U.S. Pat. No. 4,639,843, the side-mounting end of the luminaire mast is provided with a bush which closes this side-mounting end. For its part, the side-mounting luminaire likewise has at the mounting part a bush which closes the tube thereof. The two bushes are screwed together by means of a central, axially guided screw serving as securing element. The outside diameter of the luminaire mast and of the mast top unit luminaire are equal in the transition region. The connection is highly specific and requires a specific luminaire mast.
It is an object of the invention to create a device for connecting the plug-in base of a side-mounting luminaire to a carrier tube, in particular to the tube of a luminaire mast, wherein the securing element effects the mutual clamping with a large clamping force, and plugging together can be performed easily without special provisions.
The object set is achieved according to the invention in that the securing element cooperates with a clamping device which, when the securing element is inserted into the tube interior, converts the clamping force directed away from said element into the tube interior into a clamping force directed outward from the tube interior, the clamping device pressing a clamping member against the inner wall of the carrier tube, which wall serves as the abutment.
The advantage of this device consists in that the clamping force between the side-mounting luminaire and the carrier tube is strengthened as a consequence of the reversal of direction of the force and comes to act more securely.
It is provided in accordance with a further embodiment of the invention that the clamping device comprises a rocker arm which is pivotably mounted in the plug-in base such that the securing element pressing from the outside inward against one rocker arm end swivels the rocker arm and presses the other rocker arm end from the inside outward against the inner wall forming the abutment of the carrier tube. Such a rocker arm has proved to be simple and very effective.
It is provided in a further embodiment of the invention that the securing element to be actuated from the outside inward is a setscrew which is known per se and which is to be provided on the side-mounting luminaire. A setscrew is an advantageous component also for the clamping device.
It is provided in a further embodiment of the invention that the plug-in base of the side-mounting luminaire can be plugged directly into an open end of the carrier tube. The setscrew acting as the securing element can thus be fully screwed into the tube or wall material of the side-mounting luminaire and is thus securely guided in the wall material.
It is provided in a further embodiment of the invention that the portion of the plug-in base inserted into the open end of the carrier tube is provided on its outside with contact ridges which extend in its longitudinal direction and, upon being plugged into the carrier tube, fit closely against the inner wall thereof.
It is provided in a further embodiment of the invention that the outside diameter of a luminaire tube which belongs to the side-mounting luminaire and which the plug-in base adjoins corresponds to the outside diameter of the carrier tube.